1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method, and a program. In particular, the invention relates to an image processing apparatus and an image processing method, and a program in which in a case where a synthesis signal composed by synthesizing a plurality of input image signals is interpolated, an image quality of the synthesis signal after the interpolation can be improved.
2. Description of the Related Art
In general, in order for a human being to feel that a moving image is smoothly displayed, it is argued that a sufficient frame rate of the moving image is 24 frames/second. However, a liquid crystal television receiver provided with a liquid crystal panel performs hold-type light emission where light emitting elements emit light on a regular basis, and as the case is different from a television receiver provided with a cathode-ray tube or a plasma display where an impulse-type light emission is performed, it is difficult for the human being to feel that the moving image is sufficiently smoothly displayed with a frame rate of 60 frames/second.
In view of the above, in recent years, in a mainstream liquid crystal television receiver, a high frame rate processing, so called double speed drive, is performed (hereinafter, which will be referred to as HFR processing). It should be noted that the HFR processing refers to a processing of increasing the frame rate by converting a moving image with a frame rate of 60 frames/second into a moving image with a frame rate of 120 frames/second, for example.
For the HFR processing, for example, an interpolation processing for interpolating an image signal between frames is used. For the interpolation processing, such a processing is devised that motion vectors contained in an input image signal in time series are obtained, and an image signal at an arbitrary time between the image signals in time series is interpolated by using the motion vector (for example, see Japanese Unexamined Patent Application Publication No. 2001-42831).
However, for example, in a case where the interpolation processing is performed on an image signal of an overlapping image where a translucent GUI (Graphical User Interface) image or an OSD (On Screen Display) image is overlapped on the moving image (hereinafter, which will be referred to as overlapping image signal), the motion of the moving image in the overlapping image affects a motion vector of the GUI image or the OSD image that is a still image, and in the overlapping image after the interpolation processing, the GUI image or the OSD image may be disturbed.
In view of the above, it is considered that the interpolation using the motion vector is not performed on the overlapping image signal of the overlapping image where the still image such as the GUI image or the OSD image is overlapped. However, in this case, the interpolation using the motion vector is stopped on an image signal of a moving image of a background other than the GUI image or the OSD image too. Thus, an image quality of the overlapping image signal after the interpolation processing is not satisfactory.
Also, for example, when ON and OFF of the overlap of the image signal of the GUI image or the OSD image are switched over in an image signal of a moving image which becomes a target of the interpolation processing, in the interpolation processing, the interpolation using the motion vector is not performed in some cases when the target image signal is erroneously recognized as an image signal generated at a scene change. In this case, the interpolation using the motion vector is not only performed on the image signal at the moment when ON and OFF of the overlap are switched over. An image where the interpolation using the motion vector is performed and an image where the interpolation using the motion vector is not performed are continuously output in terms of time as the image after the interpolation processing, and the image after the interpolation processing is disturbed. In view of the above, it is considered that the interpolation using the motion vector is not performed during a certain period of time immediately after ON and OFF of the overlap are switched over.
On the other hand, in recent years, with the television receiver, it is becoming possible to view not only television broadcasting but also contents of the internet, and the like. Therefore, in the interpolation processing, it is preferable to consider that a synthesis signal composed by synthesizing a plurality of input image signals such as image signals of the television broadcasting, image signals of the contents of the internet, and the like is set as the target.